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Workshop on the Evolution of human Cognition

FRIDAY, 18 MARCH 2011 ICC AUDITORIUM

Sponsored by the Interdisciplinary Program in Cognitive Science, Georgetown University

PROGRAM

9:00 Introduction: Cognition and the challenge for evolution theory
David Lightfoot, Linguistics, Georgetown University

The great challenge of cognition is to understand how the human brain secretes (Darwin's word) the faculties of number, language, music, etc. These faculties evolved as there was a change in the brain, a new biochemistry, anatomy or connectivity at the genomic level with corresponding new behaviors. There is good reason to believe that many behavioral properties changed as a result of a single evolutionary development at the genomic level. It defies belief that that clustering of properties can be explained entirely by the external forces that shape natural selection; physical and biochemical constraints on the brain system are other forces that determine possibilities.

The lineage leading to Homo sapiens has undergone a substantial change in brain size and organization. As a result, modern humans display striking differences from the living apes in the realm of cognition and linguistic expression. These modern human-specific behavioral adaptations appear to be correlated with enlargement of the neocortex and related structures. Accompanying this general neocortical expansion, certain higher-order unimodal and multimodal cortical areas have grown disproportionately relative to primary cortical areas. Anatomical and molecular changes have also been identified that might relate to the modern human brain's greater metabolic demand and enhanced synaptic plasticity. Finally, the unique brain growth trajectory of modern humans has made a significant contribution to our species' cognitive and linguistic abilities.

10:30 The development and evolution of the human mathematical mind
Elizabeth M. Brannon, Psychology and Neuroscience, Duke University

Adult humans quantify, label, and categorize almost every aspect of the world with numbers. The ability to use numbers is one of the most complex cognitive abilities that humans possess and is often held up as a defining feature of the human mind. In my talk I will present a body of data that demonstrates that there are strong developmental and evolutionary precursors to adult mathematical cognition that can be seen by studying human infants and nonhuman primates. Developmental data and controversies will be discussed in light of comparative research with monkeys and other animals allowing us to see both parallels and discontinuities in the evolutionary and developmental building blocks of adult human cognition.

11:30 Speaking off the record: what the archaeological record can and cannot tell us about the origins of language and symbolic behavior
Alison S. Brooks, Anthropology, George Washington University and Smithsonian Institution Human Origins Program

In Europe, Africa and Asia, carved and painted images dating to the final millennia of the Pleistocene, along with a rich diversity of personal ornaments, musical instruments, and complex burial practices testify to the elaborate nature of symbolic behavior among anatomically modern humans, behavior which must necessarily have incorporated fully syntactic language. Despite arguments to the contrary, it seems unlikely that these complex behaviors and language itself arose suddenly in response to a one or a few genetic mutations. The earlier evidence for similar behavior as well as for language exists in more nuanced forms, and may be found in an examination of increasingly complex technological systems, greater exchange networks, and a more limited array of clearly symbolic activities of far greater antiquity, centered primarily in Africa. As this evidence predates the oldest known fossil representatives of our species, the development of symbolic behavior may be implicated in the actual evolution of modern humans themselves.

1:00 Evolution of language and the brain
Tom Schoenemann, Anthropology, Indiana University

Language evolution is a special case of the more general phenomenon of behavioral evolution. Applying evolutionary principles to the question of language evolution leads to the recognition that behavioral change (made possible by behavioral flexibility) likely drove any subsequent biological change, rather than the reverse. Among other things, this means that any pre-existing cognitive structures that could be harnessed for increasing communicative efficacy, would then likely have been co-opted for this purpose. In addition, the simpler the cognitive structures one supposes are required for language, the farther back in evolutionary time those structures likely trace their ancestry. I will argue that language evolution is best understood as an emergent phenomenon resulting from the evolution of an increasingly rich and subtle conceptual understanding of the world, within the context of an increasingly complex socially-interactive existence. It will be shown that the details of hominin brain evolution, as well as some perspectives on language itself, are consistent with these views.

Hauser, Chomsky and Fitch (2002) offers an attractive program for research into human language origins that distinguishes the internal computational system (Faculty of language--narrow sense) from the internal computational system plus its accompanying "sensory-motor" and "conceptual-intentional" systems (Faculty of language--broad sense). On this picture, FLN represents the uniquely human aspects of natural language whereas "many aspects of FLB are shared with other vertebrates" (p.1571). They apply their distinction to the grammar as a whole, arguing that narrow syntax/recursion comprises FLN whereas other subsystems of grammar (phonology, semantics) do not.

In this talk we explore whether the FLN/FLB distinction might be applied within separate components of the grammar, so that, for example, we might talk of broad vs. narrow aspects of the lexicon. Specifically, we discuss recent intriguing results by Jaspers (2011), who argues for a homology between the structure of classical Aristotelian logical concepts and the structure of human color percepts. Jaspers suggests that a small subset of logical and color terms appears to be organized by a small set of conceptual oppositions, whereas the residue appears to be organized by quite different principles. This difference manifests itself, for example, in the fact that system-licensed distinctions are very commonly lexicalized, as if by conceptual pressure, whereas lexicalization of the residue is a largely a function of utility/frequency. One way of viewing this is that the lexicon includes a narrow part, that is susceptible to algorithmic decompositional analysis, and a broad part that is not.

Evolutionary biology has considerably altered our understanding of life, and now it promises to enhance our understanding of human existence by providing new insights into the meaning of intelligence, ethical aspiration and religious life. For some scientific thinkers (especially those who espouse a "materialist" worldview), Darwin's science seems so impressive that it now replaces theology by providing the ultimate explanation of all manifestations of life, including human cognition. By focusing on human intelligence as an emergent aspect of nature this lecture asks whether a theological perspective on the universe can still have an illuminating role to play alongside of biology (and other scientific perspectives) in coming to a deeper understanding of what is really going on in human cognitive processes.